Water bugs are found in all sorts of different types of freshwater have to return to the surface of the water from time to time. Ponds and lakes are the best habitats for water bugs. Only a few species live in streams and rivers, except where the current is slow-flowing.
Adult water beetles have to breathe air. They do not have gills. Many have a supply of air beneath their wing cases or under the body which they renew from time to time. Watch a beetle in a tank. Some species come to the surface tail-first, while a few come to the surface head first. Count the number of times a beetle will visit the surface in an hour.
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Fact File: Place a needle on a piece of paper in some water. As the paper sinks, the needle floats, showing surface tension. This same process allows the water boatman to ‘walk’ on water. It uses its legs like oars to swim. |
Picture Credit : Google